Lying Overhead Reach Lie on your back with your hips and knees both at 90-degree angles, using your low abs to press your lower back into the mat. Holding five- to eight-pound dumbbells, raise your arms toward the ceiling, keeping the elbow joint slightly bent. Reach your arms overhead, tapping the dumbbells on the floor above your head. Do not let your back arch away from the floor as you lower the weights. Raise your arms back to the starting position to complete one rep. Image Source: Getty / skynesher